New Delhi: Kawasaki disease (KD) is an acute illness presenting with fever and rash, most often in children less than 5 years of age. It is one of the leading causes of acquired heart disease in children in developed countries. The causative agent for this illness is not known. The disease can be seen in clusters, more common in winter and spring months. It is more common in northeast Asian countries, with Japan having the highest incidence of KD in the world.
Talking about the incidence of Kawasaki disease in India, Dr. Kavya Mallikarjun, Consultant – Paediatric Cardiology, Manipal Hospital Old Airport Road, issued a word of caution and advised parents to be wary of this condition that may eventually lead to heart disease.
Challenges in KD Diagnosis:
The annual incidence of Kawasaki disease in India in children under 5 years of age is approximately between 60-150/100000. In our country, a significant percentage of children are older than 5 years of age – this poses a major challenge in making a diagnosis in this age group. In young infants (less than 6 months of age), the classical manifestations of KD may not be evident, which again makes the diagnosis of KD difficult in this subset of patients. KD also closely mimics other common childhood illnesses like measles and other viral exanthema.
What Happens When KD Goes Undiagnosed?
Many children with KD go undiagnosed due to a lack of awareness about this disease. The consequences of a missed diagnosis of KD can be grave due to the involvement of the coronary arteries (arteries supplying blood to the heart). The incidence of coronary artery aneurysms (coronary arteries become dilated) in untreated KD is almost 25%. With treatment, the incidence of coronary artery aneurysms is less than 4%.
Signs & Symptoms:
The most common presenting feature of Kawasaki disease is fever. The symptoms and signs of KD in children are fever lasting for more than 5 days, lymphadenopathy (unilateral), rash, bilateral non-exudative conjunctival injection (redness of the eyes), swelling and erythema (redness) of the hands and feet, and oropharyngeal findings, including strawberry tongue and erythematous lips. The other important clinical clue is the reactivation of BCG scar.
Diagnosis of KD needs a high index of suspicion. Laboratory features like raised inflammatory markers (ESR and CRP), increased platelet count, altered liver function tests, anaemia, and urinary protein can be seen. An echocardiogram is an important modality in diagnosing cardiac involvement in KD. The presence of coronary artery aneurysms is very suggestive of KD, especially when there is a diagnostic dilemma regarding the disease. Other findings like cardiac dysfunction, valve regurgitations, and pericardial effusion (fluid around the heart) can be seen on an echocardiogram. It is important to ask for an Echocardiogram early in children with suspected KD as the main long-term sequelae are coronary artery aneurysms, especially in children with untreated KD. Rarely a cardiac CT scan or an MRI may be required to assess the coronary arteries.
Treatment of KD:
The mainstay of treatment in children with KD is IVIG (intravenous immunoglobulin). The incidence of coronary artery dilatation can be reduced by giving IVIG early in the course of the illness (within 10 days). Some children may benefit from the addition of steroids along with IVIG. Aspirin is very useful as an adjunctive therapy and may need to be continued long time based on coronary artery involvement. In cases of large coronary artery aneurysms, there may be a need for anticoagulant (blood thinners) therapy. In very rare situations, wherein there is resistance to IVIG, the use of other medications may be considered.
As highlighted previously, the long-term consequences of a missed diagnosis of KD can be devastating. Once a giant or large coronary artery aneurysm develops, it can be irreversible. Long-term surveillance is necessary in patients with coronary artery aneurysms especially in those with large or giant aneurysms 1 year after KD onset. The sequelae of cardiac involvement can be lifelong with the need for investigations and therapy, hence the importance of early diagnosis of this illness in childhood. Most of the long-term sequelae of KD can be prevented by early intervention.
The annual incidence of Kawasaki disease in India in children under 5 years of age is approximately between 60-150/100000. In our country, a significant percentage of children are older than 5 years of age – this poses a major challenge in making a diagnosis in this age group. Health News Health News: Latest News from Health Care, Mental Health, Weight Loss, Disease, Nutrition, Healthcare
